1. Fields of the Invention
The present invention relates to a nozzle assembly for a sprinkler, especially to a nozzle assembly for a sprinkler that can provide on-off control of water and regulate the amount of water output.
2. Descriptions of Related Art
A nozzle assembly for conventional underground sprinklers is revealed. Refer to U.S. Pat. No. 5,086,977 “SPRINKLER DEVICE”, underground sprinklers in which water pressure causes a pop-up riser means being moved to its extend or retracted position are disclosed. A nozzle assembly is mounted in an axially movable nozzle housing assembly that is received in a cylindrical housing. An opening is formed in the outer surface of the nozzle housing and a nozzle is inserted through the opening into the nozzle housing assembly. The top of a cylindrical member of the riser means has an adjusting slot for setting the desired oscillating angle for the sprinkler. After water flowing through, the nozzle assembly is popped up slowly to a preset position and then water is ejected from the nozzle.
The amount of water output though the above nozzle assembly is unable to be adjusted. Thus the water flow ejected out from the nozzle assembly is delivered to a certain range. The water flow is unable to be modified according to terrain and users' requirements.
A nozzle assembly with adjustable water output has been developed and invented based on the structure of the above underground sprinklers. Refer to U.S. Pat. No. 6,241,158 “Irrigation sprinkler with pivoting throttle valve” and U.S. Pat. No. 6,050,502 “Rotary sprinkler with memory arc mechanism and throttling valve”, a pivotable arc valve body is arranged on a vertical water channel, located in a riser just below the nozzle. The arc valve is pivotable between two positions by manually turning a drive member with a hand tool. When the valve body pivots to its first (vertical) position, the water flow path is substantially open while the valve body substantially obstructs the water flow path when it pivots to a second (horizontal) position.
Although the above nozzle assemblies provide functions of on-off and water flow adjustment, they still have following shortcomings:    1. The arc valve body of the nozzle assembly is set and pivoted in the vertical water channel. The space inside the vertical water channel is small and narrow and this causes difficulties in assembling the arc valve body.    2. Through a gear drive assembly operated by a hand tool, the nozzle is rotated by the arc valve body in above two patents. Thereby the operation of the drive assembly is not smooth once the connection between the drive member and the arc valve body is poor. On the other hand, once the connection therebetween is good, the arc valve body is difficult to be located precisely. When the arc valve body is in the closed position, it is easy to be moved due to flow pressure and the water flow path is opened automatically.    3. The drive member is mounted in the upper end of the nozzle assembly and is parallel to the vertical water channel of the nozzle assembly. Thus the top of a driving end of the drive member is exposed on a top surface of the nozzle assembly for convenience of moving and adjusting the drive member. However, everyone can easily change the water flow if he intends and there is no protection design.
Thus there is a space to improve the nozzle assembly available now and a need to provide the nozzle assembly with novel design.